1. Field
Aspects of the present invention generally relate to a power supply apparatus, a power supply method, and a storage medium.
2. Description of the Related Art
Conventionally, there has been provided a technique for supplying electric power in a non-contact manner (a wireless manner). There are four types of wireless power supply methods, that is, an electromagnetic induction method, a magnetic field resonance method, an electric field coupling method, and a radio wave receiving method. Among these methods, the magnetic field resonance method can transmit a sufficient amount of electric power over a long distance as its feature. With such characteristics, the magnetic field resonance method has especially received attention among these four methods. In the magnetic field resonance method, a one-to-N power supply method using the long-distance power transmission capability has been discussed (see, e.g., Japanese Patent Application Laid-Open No. 2009-136132). This one-to-N power supply method enables a power supply apparatus to wirelessly transmit electric power to a plurality of power receiving apparatuses. In the technique discussed in Japanese Patent Application Laid-Open No. 2009-136132, the power supply apparatus transmits a predetermined pulse signal during a standby mode in which electric power is not transmitted. With the pulse signal, the power supply apparatus searches for a power receiving apparatus in proximity thereof within several meters. When the power receiving apparatus transmits a unique ID thereof to the power supply apparatus, the power supply apparatus determines whether a transmission source of the unique ID is a power receiving apparatus as a power supply target. If the transmission source of the unique ID is the power receiving apparatus as the power supply target, the power supply apparatus supplies electric power to the power receiving apparatus. The power supply apparatus can transmit a unique code to the power receiving apparatus so that the power supply apparatus separately receives information such as a charging amount and a device state.
The power supply apparatus can perform data communications with the power receiving apparatus in a communication area. This communication area is generally larger than a power supply area in which the power supply apparatus can supply electric power to the power receiving apparatus. Accordingly, when the power receiving apparatus is positioned inside the communication area and outside the power supply area of the power supply apparatus, there are cases where the power supply apparatus determines the power receiving apparatus as a power supply target. However, when the power supply apparatus supplies electric power, an appropriate amount of the electric power cannot be supplied to the power receiving apparatus. That is, the electric power is wasted.